JP2009084345A - Water-soluble azo compound or its salt, ink composition and colored material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a yellow dye having highly bright hue suitable for inkjet recording, producing a recorded matter having various good fastness properties and giving an ink composition having excellent storage stability, and to provide an ink composition containing the dye. <P>SOLUTION: The invention provides a water-soluble azo compound expressed by formula (1), its salt and the use of the compounds. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water-soluble azo compound or a salt thereof, an ink composition containing the same, and a colored product colored with the ink composition.

Among various color recording methods, a recording method using an ink jet printer, which is one of the representative methods, has developed various ink ejection methods, all of which generate ink droplets, Recording is performed by attaching to a recording material (paper, film, fabric, etc.). This method has been rapidly spreading in recent years because of the features that the recording head and the recording material are not in direct contact, so there is no sound generation and is quiet, and the size, speed and color are easy. Large growth is expected in the future. Conventionally, inks such as fountain pens and felt pens and inks for ink jet recording have been used inks in which a water-soluble dye is dissolved in an aqueous medium. In order to prevent clogging, a water-soluble organic solvent is generally added. These inks provide a recording image with sufficient density, do not cause clogging of the pen tip and nozzles, have good drying properties on the recording material, have little bleeding, and have excellent storage stability. Is required. The formed recorded image is required to have fastness such as water resistance, moisture resistance, light resistance, and gas resistance.
Ink-jet nozzle clogging occurs when the water content in the ink evaporates near other nozzles and other solvents and additives, and the dye crystallizes and precipitates when the composition state is low in water and high in solvents and additives. There are many things derived from this. Therefore, it is one of the very important required performances that crystals do not easily precipitate even when the ink is evaporated and dried. For this reason, high solubility in solvents and additives is one of the properties required for pigments.

  By the way, in order to record an image or character information on a color display of a computer in color by an ink jet printer, generally a subtraction method using four colors of ink of yellow (Y), magenta (M), cyan (C), and black (K). Mixed colors are used, whereby the recorded image is expressed in color. In order to reproduce the additive color mixture image of red (R), green (G), and blue (B) on a CRT (CRT) display etc. as faithfully as possible with the subtractive color mixture image, each dye used in the ink, especially Y, It is desired that each of M and C has a hue close to a standard and is clear. In addition, the ink is stable for long-term storage, has a high density of the printed image as described above, and has excellent fastness such as water resistance, moisture resistance, light resistance and gas resistance. Desired.

  Due to recent developments in inkjet technology, the speed of inkjet printing has been dramatically improved, and the use of inkjet printers, such as laser printers that use electronic toner, to print documents on plain paper, which is the main application in the office environment Is out. Ink jet printers have the advantage that the type of recording paper is not limited and the price of the machine is low. In particular, ink jet printers are spreading in small to medium-sized office environments such as SOHO. As described above, when an inkjet printer is used for printing on plain paper, hue and water resistance tend to be more important in the quality required for printed matter. In order to satisfy these performances, a method of using a pigment ink has been proposed. However, since a pigment ink is a dispersed ink in which a pigment does not dissolve in a water-based ink, the stability of the ink itself can be obtained by using this. And the problem of clogging of the nozzles of the head occur, and when pigment ink is used, there are many problems in terms of abrasion resistance. In the case of a dye ink, such a problem is considered to be relatively difficult to occur. However, in particular, the water resistance is extremely inferior to that of a pigment ink, and an improvement to the problem is strongly desired.

  Many proposals have been made for the problem of improving water resistance on plain paper. For example, a dye described in Patent Document 1 has been proposed as a yellow colorant for inkjet which has excellent water resistance and improved hue and light resistance.

JP-A-4-233975

The dye described in Patent Document 1 is very excellent in water resistance for a specific type of plain paper, but its high water resistance is widely effective for many types of commercially available plain paper. It cannot be said that Further, the dye described in Patent Document 1 has a problem that the saturation as a yellow color when printed is low, and the color development range becomes narrow particularly on plain paper. Accordingly, there has been a demand for the development of a yellow color pigment that is further improved in terms of water resistance and saturation, as well as hue and print density.
The present invention has high solubility in water or a water-soluble organic solvent, has a hue and saturation suitable for ink jet recording, has a high color density, and has light resistance, gas resistance, moisture resistance, and particularly water resistance of the recorded matter. It is an object of the present invention to provide a water-soluble yellow colorant (compound) excellent in fastness such as the above and an ink composition having good storage stability containing the same.

As a result of intensive investigations, the present inventors have found that a water-soluble tetraazo compound represented by a specific formula and an ink composition containing the same solve the above-described problems. Was completed.
That is, the present invention is (1)
A water-soluble azo compound represented by the following formula (1) or a salt thereof,

(In the formula (1), R represents an alkyl group having 1 to 4 carbon atoms,
n is an integer of 1 or 2,
x is an integer from 2 to 4,
The group A represents a divalent linking group represented by any one of the following general formulas (2) to (4). )

(In formula (2), y represents an integer of 2 to 6.)

(In formula (4), w represents an integer of 1 to 4.)

(2)
The water-soluble azo compound or a salt thereof according to the above (1), wherein R in formula (1) is a methyl group, n is 1, and x is 3

(3)
The water-soluble azo compound or a salt thereof according to the above (1) represented by the following formula (5):

(4)
An ink composition containing the water-soluble azo compound or a salt thereof according to any one of (1) to (3) as a pigment;
(5)
The ink composition according to (4), further comprising a water-soluble organic solvent;
(6)
The ink composition according to (4) or (5), which is for inkjet recording;
(7)
In an ink jet recording method in which ink droplets are ejected according to a recording signal to record on a recording material, the ink composition according to any one of (4) to (6) is used as ink. An inkjet recording method,
(8)
The inkjet recording method according to (7), wherein the recording material is an information transmission sheet,
(9)
The inkjet recording method according to (8), wherein the information transmission sheet is a sheet having an ink receiving layer containing plain paper and a porous white inorganic substance,
(10)
A colored body colored with the water-soluble azo compound according to any one of (1) to (3) or the ink composition according to any one of (4) to (6);
(11)
The colored body according to (10), wherein coloring is performed by an inkjet printer,
(12)
An inkjet printer loaded with a container containing the ink composition according to any one of (4) to (6),
About.

The water-soluble azo compound represented by the above formula (1) or a salt thereof of the present invention is excellent in solubility in water or a water-soluble organic solvent. Further, it has a feature of good filterability, for example, with respect to a membrane filter in the process of producing an ink composition, and gives a very clear and high yellow hue on plain paper and inkjet recording paper. Further, the ink composition of the present invention containing this compound has very good storage stability without crystal precipitation, physical property change, hue change and the like after long-term storage. A printed matter using the ink composition of the present invention as an ink for ink jet recording has an ideal hue as a yellow hue without selecting a recording material (for example, paper, film, etc.), and a photographic color image Can be reproduced faithfully on paper.
Furthermore, the ink composition of the present invention has extremely improved water resistance on plain paper compared to conventional dye inks. In addition, even when recording on a recording material coated with a porous white inorganic material such as paper for exclusive use for photographic image quality and film, it has various fastness properties, that is, water resistance, moisture resistance, gas resistance, and light resistance. It is good and has excellent long-term storage stability of photographic recorded images. Thus, the water-soluble azo compound of the formula (1) is extremely useful as a yellow color pigment for inks, particularly for inkjet recording inks.

The present invention will be described in detail. In the present specification, unless otherwise specified, acidic functional groups such as sulfo group and carboxy group are represented in the form of free acid.
In the following description, unless otherwise specified, for convenience, the “water-soluble azo compound of the present invention or a salt thereof” or “the compound of the present invention” is referred to as “the dye of the present invention”, or in some cases, simply “ It is expressed as “dye”.
The coloring matter of the present invention is represented by the above formula (1).
In the formula (1), R is an alkyl group having 1 to 4 carbon atoms, n is an integer of 1 or 2, x is an integer of 2 to 4, and the group A is any one of the above formulas (2) to (4). Or a single divalent linking group.

In the formula (1), R represents an alkyl group having 1 to 4 carbon atoms and may be either a straight chain or a branched chain, but a straight chain is more preferable. Specific examples include linear chains such as methyl, ethyl, n-propyl, and n-butyl; branched chains such as isopropyl, isobutyl, sec-butyl, and t-butyl. All of these are preferred, but a methyl group is particularly preferred.

In the formula (1), n represents an integer of 1 or 2, and both are preferable, but 1 is particularly preferable.
x represents an integer of 2 to 4, and any one is preferable, but 3 is particularly preferable.

When A in the above formula (1) is the above formula (2), y in the formula (2) represents an integer of 2 to 6. The number is preferably 2 to 4, particularly preferably 2.

When A in the above formula (1) is the above formula (4), w in the formula (4) represents an integer of 1 to 4. Although all are preferable, 4 is particularly preferable.

As A in the above formula (1), the above formulas (2) to (4) are all preferred, but the case of the above formula (4) is particularly preferred. Moreover, the compound which combined said preferable things is more preferable, and the compound which combined more preferable things is further more preferable. The same applies to particularly preferable ones.
Among the above combinations, the compound of the above formula (1) in a particularly preferable combination is the compound of the above formula (5).

  The compound of the above formula (1) exists also as a free acid or a salt thereof. Examples of the salt of the compound of the formula (1) include salts with inorganic or organic cations. Specific examples of the inorganic cation salt include alkali metal salts such as lithium, sodium, potassium and the like. Examples of organic cations include, but are not limited to, salts of compounds represented by the following formula (6).

(In the formula (6) represents a Z ¹ to Z ⁴ each independently represent a hydrogen atom, C1 -C4 alkyl, hydroxy C1 -C4 alkyl group or a hydroxy C1 -C4 alkoxy C1 -C4 alkyl group.)

Here, examples of the alkyl group in Z ^{1 to} Z ⁴ include methyl, ethyl and the like, and examples of the hydroxyalkyl group include hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxy Examples of the hydroxyalkoxyalkyl group include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3- (hydroxyethoxy) propyl, and 3- (hydroxyethoxy). Examples include butyl and 2- (hydroxyethoxy) butyl.

  Preferable examples of the salt include sodium, potassium, lithium, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine salt, and ammonium salt. Of these, lithium, sodium, and ammonium salts are particularly preferred.

As will be apparent to those skilled in the art, the salt of the compound of the above formula (1) can be easily obtained by the following method.
For example, salt is added to a reaction solution before adding 800 parts of acetone in Example 1 described later, or an aqueous solution in which a wet cake containing a compound of the formula (1) or a dried product of the compound of the formula (1) is dissolved to add a salt. The sodium salt of the compound of the above formula (1) can be obtained as a wet cake by analyzing and filtering the precipitated solid.
Further, after dissolving the obtained sodium salt wet cake in water, an acid such as hydrochloric acid is added to adjust the pH appropriately, and the precipitated solid is filtered to obtain the free acid of the compound of the above formula (1). Alternatively, a mixture of a free acid and a sodium salt in which a part of the compound of the formula (1) is a sodium salt can be obtained.
Further, while stirring the wet cake of the free acid of the compound of the formula (1) with water, for example, potassium hydroxide, lithium hydroxide, ammonia water or a hydroxide of the formula (6) is added to make it alkaline. For example, a corresponding potassium, lithium, ammonium, or quaternary ammonium salt can be obtained. By limiting the number of moles of the above-mentioned salt to the number of moles of free acid, it is possible to prepare, for example, a mixed salt of lithium and sodium, and further a mixed salt of lithium, sodium, and ammonium. is there. The salt of the compound of the above formula (1) may change the physical properties such as solubility or the ink performance when used as an ink depending on the type of the salt. For this reason, it is also preferable to select the type of salt according to the target ink performance.
Among these salts, lithium, sodium, and ammonium salts are particularly preferable as described above.

The pigment | dye shown by the said Formula (1) of this invention can be manufactured as follows, for example. In addition, R, n, w, x, and y used appropriately in the following formulas (AA) to (G) represent the same meaning as in the above formula (1).
The compound of the following formula (C) is obtained by diazotizing the aminobenzenecarboxylic acid represented by the following formula (AA) and performing a coupling reaction with the compound of the following formula (B) at 0 to 25 ° C. and pH 3 to 4. It is done.

  Next, by condensing the obtained compound (2 equivalents) of the above formula (C) and cyanuric halide such as cyanuric chloride at a temperature of 25 to 45 ° C. and a pH of 5 to 7.5, the following formula (D) A compound is obtained.

  Further, the chlorine atom in the obtained compound of the above formula (D) is preferably represented by any one of the following general formulas (E) to (G) under the conditions of 75 to 90 ° C. and pH 7 to 9. By substituting with a compound, the dye of the present invention represented by the above formula (1) can be obtained.

Specific examples of the compound of the formula (AA) include 4-aminobenzoic acid, 3-aminobenzoic acid, 2-aminobenzoic acid, 5-aminoisophthalic acid, 2-aminoterephthalic acid, and the like. Specific examples of the compound B) include 2- (sulfoethoxy) -5-methylaniline, 2- (sulfopropoxy) -5-methylaniline, 2- (sulfobutoxy) -5-methylaniline and the like.
Examples of the compound of the above formula (E) include ethylene diamine, propylene diamine, butylene diamine, pentamethylene diamine, hexamethylene diamine and the like, and examples of the compound of the above formula (G) include 2,3-diaminopropionic acid. Specific examples include 2,4-diaminobutyric acid, 2,5-diaminovaleric acid, and 2,6-diaminohexanoic acid.

  Next, specific examples of the dye of the present invention are shown in Table 1 below. In Table 1, acidic functional groups such as carboxy and sulfo are represented in free acid form.

The dye of the above formula (1) of the present invention can be isolated as a solid free acid by adding a mineral acid such as hydrochloric acid after the coupling reaction, and the resulting free acid solid is water or, for example, aqueous hydrochloric acid. Inorganic salts contained as impurities, such as sodium chloride and sodium sulfate, can be removed by washing with acidic water such as.
By treating the free acid of the dye of the present invention obtained as described above with a desired inorganic or organic base in an aqueous medium as described above, a solution of the corresponding dye salt can be obtained. The aqueous medium usually means a mixed solution of a water-soluble organic solvent and water. However, although it is not usually classified as an organic solvent, a substance that becomes an aqueous solution by mixing with water, such as urea, can be used as the medium for the base treatment. Therefore, it includes the aqueous solution of such a substance, and is described as an aqueous medium in this specification. However, urea is generally classified as a dye solubilizer.
Examples of the inorganic base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, or alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate, and ammonium hydroxide. It is done.
Examples of the organic base include, but are not limited to, salts of organic amines represented by the above formula (6), such as salts of alkanolamines such as diethanolamine and triethanolamine.

The coloring matter of the present invention is suitable for dyeing natural and synthetic fiber materials or blended products, and also for producing writing ink and ink composition for ink jet recording.
The reaction liquid containing the pigment of the above formula (1) of the present invention (for example, the reaction liquid before adding 800 parts of acetone in Example 1 described later) is directly used for the production of the ink composition of the present invention. You can also. However, after isolating the compound from the reaction solution, for example, by drying the reaction solution or the like by a method such as spray drying, the compound can be isolated and then processed into an ink composition. The ink composition of the present invention is generally 0.1 to 20% by mass, more preferably 1 to 10% by mass, and still more preferably 2% of the dye of the formula (1) in the aqueous solution in the total mass of the ink composition. Contains ~ 8% by mass.

  In the ink composition of the present invention, the dye of the formula (1) is dissolved in an aqueous medium such as water and / or a water-soluble organic solvent (an organic solvent that can be mixed with water), and an ink adjusting agent is added as necessary. It is what was added. When this ink composition is used as an ink for an ink jet printer, it is preferable to use a metal cation chloride contained as an impurity, such as sodium chloride, sulfate, eg, an inorganic substance such as sodium sulfate. . In this case, for example, the total content of sodium chloride and sodium sulfate is about 1% by mass or less with respect to the total mass of the dye, and the lower limit may be 0% by mass, that is, the detection limit of the detection instrument or less. In order to produce a pigment with a small amount of inorganic substances, for example, a method using a known reverse osmosis membrane or a dried product or wet cake of a compound of the present invention or a salt thereof in a mixed solvent of water such as C1-C4 alkanol such as methanol and water. The suspension may be purified by suspension, and the solid may be filtered and dried for desalting.

  The ink composition of the present invention is prepared using water as a medium, and may contain a water-soluble organic solvent as necessary within a range that does not impair the effects of the present invention. Water-soluble organic solvents are used as dye solubilizers, drying inhibitors (wetting agents), viscosity modifiers, penetration enhancers, surface tension modifiers, antifoaming agents, and the like. Other ink preparation agents include, for example, antiseptic / antifungal agents, pH adjusting agents, chelating reagents, rust preventing agents, UV absorbers, viscosity adjusting agents, dye dissolving agents, antifading agents, emulsion stabilizers, surface tension adjusting agents. , Known additives such as antifoaming agents, dispersants, and dispersion stabilizers. The content of the water-soluble organic solvent is 0 to 60% by mass, preferably 10 to 50% by mass with respect to the total mass of the ink, and the ink preparation agent is 0 to 20% by mass, preferably 0 to 0% by mass. It is preferable to use 15% by mass. The remainder other than the above is water.

  Examples of the water-soluble organic solvent include C1-C4 alkanols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol and tert-butanol; N, N-dimethylformamide or N, Amides such as N-dimethylacetamide; 2-pyrrolidone, N-methyl-2-pyrrolidone, hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido- Heterocyclic ketones such as 2-one; ketones or ketoalcohols such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one; cyclic ethers such as tetrahydrofuran, dioxane; ethylene glycol, 1, 2- or 1 , 3-Propylene glycol 1,2- or 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, or thiodiglycol, etc., C2-C6 Mono, oligo or polyalkylene glycol or thioglycol having an alkylene unit; polyol (triol) such as glycerin, hexane-1,2,6-triol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol mono Ethyl ether, diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monomethyl Ethers, C1 -C4 mono-alkyl ethers of polyhydric alcohol such as triethylene glycol monoethyl ether; .gamma.-butyrolactone or dimethyl sulfoxide and the like.

  Preferred as the above water-soluble organic solvent are isopropanol, glycerin, mono, di or triethylene glycol, dipropylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol, more preferably isopropanol, Glycerin, diethylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol. These water-soluble organic solvents are used alone or in combination.

Examples of the antiseptic / antifungal agent include organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, benzothiazole, nitrile, pyridine, 8-oxyquinoline, isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, adamantane, dithiocarbamate, bromo Indanone-based compounds, benzyl bromoacetate compounds, and inorganic salt compounds are exemplified.
Examples of the organic halogen compound include sodium pentachlorophenol, examples of the pyridine oxide compound include sodium 2-pyridinethiol-1-oxide, and examples of the inorganic salt compound include sodium acetate. Examples of the isothiazoline-based compound include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 5 -Chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride, etc. Can be mentioned.
Other antiseptic and antifungal agents include sodium sorbate and sodium benzoate. Other specific examples of antiseptic / antifungal agents include, for example, trade names Proxel GXL (S) and Proxel XL-2 (S) manufactured by Avecia.

  As the pH adjuster, any substance can be used as long as it can control the pH of the ink within the range of 6.0 to 11.0 for the purpose of improving the storage stability of the ink. For example, alkanolamines such as diethanolamine and triethanolamine, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide, or alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate. And carbonates.

  Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate and the like.

  Examples of the rust preventive include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

  Examples of the ultraviolet absorber include a compound that emits fluorescence by absorbing ultraviolet rays typified by benzophenone compounds, benzotriazole compounds, cinnamic acid compounds, triazine compounds, stilbene compounds, or benzoxazole compounds, so-called fluorescence. Brightening agents can also be used.

  Examples of the viscosity modifier include water-soluble polymer compounds in addition to water-soluble organic solvents, such as polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

  Examples of the dye solubilizer include urea, ε-caprolactam, ethylene carbonate, and the like. It is preferred to use urea.

  The anti-fading agent is used for the purpose of improving image storage stability. As the antifading agent, various organic and metal complex antifading agents can be used. Examples of organic antifading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. There are nickel complexes and zinc complexes.

  Examples of the surface tension adjusting agent include surfactants, and examples include anionic surfactants, amphoteric surfactants, cationic surfactants, and nonionic surfactants.

  Anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and their salts, N-acyl methyl taurates, alkyl sulfates polyoxyalkyl ether sulfates Salt, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkyl allyl sulfonate, diethyl sulfosuccinate , Diethylhexylsyl sulfosuccinate, dioctyl sulfosuccinate and the like.

  Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, and other imidazoline derivatives. There is.

  Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Ethers such as alkyl ethers; polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene mono Esters such as oleate and polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4, -Acetylene glycol (alcohol) type such as diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol, and other specific examples such as Nissin Examples include trade name Surfynol 104, 82, 465, Olphine STG, etc. manufactured by Kagakusha.

  As the antifoaming agent, a highly oxidized oil-based, glycerin fatty acid ester-based, fluorine-based, or silicone-based compound is used as necessary.

  These ink preparation agents are used alone or in combination. The surface tension of the ink of the present invention is usually 25 to 70 mN / m, more preferably 25 to 60 mN / m. The viscosity of the ink of the present invention is preferably 30 mPa · s or less. Furthermore, it is more preferable to adjust to 20 mPa · s or less.

  In order to produce the ink composition of the present invention, there is no particular limitation on the order of dissolving each agent such as an additive. In preparing the ink, the water to be used is preferably one having few impurities such as ion exchange water or distilled water. Furthermore, if necessary, fine filtration may be performed using a membrane filter to remove impurities. When used as ink for an inkjet printer, it is preferable to perform fine filtration. The pore diameter of the filter for performing microfiltration is usually 1 to 0.1 microns, preferably 0.8 to 0.2 microns.

  The ink composition containing the coloring matter of the present invention is suitable for use in printing, copying, marking, writing, drawing, stamping, or recording (printing), particularly in inkjet recording. In addition, the ink composition of the present invention hardly causes crystal precipitation even when dried in the vicinity of the nozzles of the ink jet printer, and for this reason, the head is not easily blocked. Furthermore, when the ink composition of the present invention is used for ink jet recording, a high-quality yellow color print having good resistance to water, light, ozone, nitrogen oxide gas, and friction can be obtained, particularly water resistance on plain paper. Is very good.

  In some inkjet printers, two types of ink, high density ink and low density ink, are loaded in one printer for the purpose of supplying a high-definition image. In that case, using the dye of the present invention, an ink composition having a high dye concentration and an ink composition having a low concentration may be prepared and used as an ink set. Moreover, you may use this pigment | dye only for either one. Moreover, you may use together the pigment | dye of this invention, and the well-known yellow color pigment | dye. In addition, the colorant of the present invention can be used for toning of other colors, for example, black ink, or for the purpose of preparing a red ink or a green ink by mixing with a magenta colorant or a cyan colorant.

  The colored body of the present invention is a substance colored with the pigment of the present invention. The material of the colored body is not particularly limited. For example, a sheet for information transmission such as paper or film, fiber or cloth (cellulose, nylon, wool, etc.), leather, a base material for a color filter, or the like may be used. Anything is acceptable and not limited to these. Examples of the coloring method include a dip dyeing method, a textile printing method, a printing method such as screen printing, and a method using an ink jet printer, and a method using an ink jet printer is preferable.

The information transmission sheet is not particularly limited, and plain paper as well as surface-treated sheets, specifically, a paper, synthetic paper, a substrate such as a film provided with an ink receiving layer, and the like are used. Here, the ink receiving layer is, for example, a method of impregnating or coating the base material with a cationic polymer; or inorganic fine particles capable of absorbing a pigment in ink such as porous silica, alumina sol, and special ceramics. A method of coating the surface of the substrate together with a hydrophilic polymer such as pyrrolidone; Those provided with such an ink receiving layer are usually called ink jet exclusive paper, ink jet exclusive film, glossy paper, or glossy film.
Plain paper refers to paper that is not particularly provided with an ink-receptive layer, and many different types of paper are commercially available depending on the application. As an example of commercially available plain paper, for inkjet, double-sided fine plain paper (manufactured by Seiko Epson Corporation), color plain paper, (manufactured by Canon Inc.), Multipurse Paper, All-in-one Printing Paper (Hewlett) Packard). In addition, PPC paper whose use is not particularly limited to ink jet printing is also plain paper.
The ink composition of the present invention is particularly excellent in water resistance on plain paper as described above, but is also excellent in resistance to other light, ozone, humidity and friction. Excellent water resistance on inkjet special paper, special film, glossy paper or glossy film with an ink receiving layer for inkjet printing, and light resistance and gas resistance on the information transmission sheet Also excellent in moisture resistance and abrasion resistance.

In order to record on a recording material by the ink jet recording method of the present invention, for example, a container filled with the ink composition described above is set at a predetermined position of an ink jet printer and recorded on the recording material by a normal method. Good. In the ink jet recording method of the present invention, inks of various colors such as magenta, cyan, and, if necessary, green, blue (or violet), red, and black can be used in combination with the ink composition of the present invention. In this case, the ink of each color is injected into each container, and these containers are used in a predetermined position of the ink jet printer.
Some inkjet printers use, for example, a piezo method using mechanical vibration, a bubble jet (registered trademark) method using bubbles generated by heating, or the like. The ink jet recording method of the present invention can be used by any method.

  The ink composition of the present invention has a clear yellow color, has a high degree of definition of an image recorded on plain paper, ink jet exclusive paper or glossy paper, and has a hue suitable for the ink jet recording method. Further, the fastness of the recorded image is very high.

  The ink composition of the present invention does not precipitate or separate during storage. Further, when the ink composition of the present invention is used for ink jet recording, crystal precipitation due to drying of the ink composition in the vicinity of the nozzle is very unlikely to occur, and the ejector (ink head) is not blocked. The ink composition of the present invention uses a continuous ink jet printer and has physical properties even when the ink is recirculated at relatively long time intervals or intermittently used by an on-demand ink jet printer. Does not change.

Hereinafter, the present invention will be described more specifically with reference to examples. In the text, “parts” and “%” are based on mass unless otherwise specified, and the reaction temperature is also the internal temperature.
In addition, (lambda) max (maximum absorption wavelength) of each compound synthesize | combined showed the measured value in pH7-8 aqueous solution. In the examples, only examples of sodium salts or ammonium salts are described, but alkali metal salts and salts with organic cations can be easily obtained by using an appropriate method as described above. The present invention is not limited to this embodiment.
Furthermore, in each structural formula of the compounds obtained in the examples, acidic functional groups such as carboxy and sulfo are represented in the form of free acid.

Example 1
13.7 parts of 3-aminobenzoic acid was dissolved in 100 parts of water while adjusting the pH to 6 with sodium hydroxide, and then 7.2 parts of sodium nitrite was added. This solution was added dropwise at 0 to 10 ° C. in 100 parts of 5% hydrochloric acid over 30 minutes, followed by stirring at 10 ° C. or lower for 1 hour to carry out a diazotization reaction to prepare a diazonium salt.
Next, 24.5 parts of 2- (sulfopropoxy) -5-methylaniline was dissolved in 200 parts of water while adjusting the pH to 7 with sodium hydroxide, added to the diazonium salt prepared above, and added at 0 to 25 ° C. The mixture was stirred at pH 3-4 for 5 hours. The precipitated solid was collected by filtration to obtain 120 parts of an azo compound (7) as a wet cake.

Next, 120 parts of the wet cake of the azo compound (7) obtained by the above method is dissolved in 300 parts of water, and 0.10 parts of Lion Corporation, trade name Leocol TD50 (surfactant) is added to this solution. Then, 6.4 parts of cyanuric chloride was added, and then stirred at pH 5 to 7.5 and 25 to 45 ° C. for 6 hours.
Next, 1.1 parts of ethylenediamine was added, and the mixture was stirred at pH 7-9 and 75-90 ° C. for 3 hours. After cooling the obtained reaction liquid to 20-40 degreeC, 800 parts of acetone was added to this reaction liquid, and it stirred at 20-40 degreeC for 1 hour. The precipitated solid was collected by filtration to obtain 100 parts of a wet cake. This wet cake was dried with a hot air dryer at 80 ° C. to obtain 29.0 parts of the water-soluble azo compound of the present invention represented by the following formula (8) as a sodium salt.

Example 2
Except that 1.1 parts of ethylenediamine in Example 1 was changed to 1.5 parts of piperazine, 29.5 parts of the water-soluble azo compound of the present invention represented by the following formula (9) was converted into a sodium salt in the same manner as in Example 1. Got as.

Example 3
The water-soluble azo compound 30 of the present invention represented by the following formula (10) was prepared in the same manner as in Example 1 except that 1.1 parts of ethylenediamine in Example 1 was changed to 2.6 parts of 2,6-diaminohexanoic acid. 0.0 part was obtained as the sodium salt.

Example 4
29.0 parts of the water-soluble azo compound of the present invention represented by the above formula (8) obtained in Example 1 was dissolved in 270 parts of water, 45 parts of ammonium chloride was added, and then adjusted to pH 3-6 with hydrochloric acid. After stirring for 30 minutes, the precipitated solid was collected by filtration to perform a salt exchange reaction from a sodium salt to an ammonium salt to obtain 120 parts of a wet cake. The wet cake was washed with 200 parts of methanol, and then dried with a hot air dryer at 80 ° C., whereby 25.0 parts of an ammonium salt (λmax 399 nm) of the water-soluble azo compound of the present invention represented by the above formula (8). Got.

Example 5
29.5 parts of the water-soluble azo compound of the present invention represented by the above formula (9) obtained in Example 2 is dissolved in 270 parts of water, 45 parts of ammonium chloride is added, and then adjusted to pH 3-6 with hydrochloric acid. After stirring for 30 minutes, the precipitated solid was collected by filtration to perform a salt exchange reaction from a sodium salt to an ammonium salt to obtain 120 parts of a wet cake. The wet cake was washed with 200 parts of methanol, and then dried with a hot air dryer at 80 ° C., whereby 25.0 parts of an ammonium salt (λmax 399 nm) of the water-soluble azo compound of the present invention represented by the above formula (9). Got.

Example 6
30.0 parts of the water-soluble azo compound of the present invention represented by the above formula (10) obtained in Example 3 is dissolved in 270 parts of water, 45 parts of ammonium chloride is added, and then adjusted to pH 3-6 with hydrochloric acid. After stirring for 30 minutes, the precipitated solid was collected by filtration to perform a salt exchange reaction from a sodium salt to an ammonium salt to obtain 120 parts of a wet cake. The wet cake was washed with 200 parts of methanol and then dried with a hot air dryer at 80 ° C., whereby 25.0 parts of an ammonium salt (λmax 407 nm) of the water-soluble azo compound of the present invention represented by the above formula (9). Got.

Examples 7-9
(A) Preparation of ink Using the azo compounds of the present invention obtained in Examples 4 to 6 above, the compositions shown in Table 2 were mixed at various composition ratios to obtain ink compositions of the present invention. . The obtained ink composition was filtered through a 0.45 μm membrane filter to remove impurities, and an ink containing the compound of the present invention was prepared. The water was ion-exchanged water, adjusted with ammonia water so that the pH of the ink composition was about 9.5, and then added so that the total amount was 100 parts. The ink using the compound of Example 4 is designated as Example 7, the ink using the compound of Example 5 is designated as Example 8, and the ink using the compound of Example 6 is designated as Example 9.

Table 2 (Composition ratio of ink composition)
Azo compound obtained in Examples 4, 5 and 6 4.0 parts Glycerin 5.0 parts Urea 5.0 parts N-methyl-2-pyrrolidone 4.0 parts Isopropyl alcohol 3.0 parts Butyl carbitol 2.0 Part Name Surfynol 104PG50 (Note) 0.1 part Ammonia water + water 76.9 parts Total 100.0 parts (Note) Acetylene glycol nonionic surfactant, manufactured by Nisshin Chemical Co., Ltd.

Comparative Example 1
Instead of the azo compounds obtained in Examples 4 to 6 as the dye component, the ink described in Example 10 of Patent Document 1 was used in the same composition ratio as in Table 2 and a comparative ink was prepared by the same operation. Prepared. The structural formula of the compound used is shown in the following formula (11). In addition, evaluation was performed using the ammonium salt of following formula (11).

(B) Inkjet printing Using an inkjet printer (trade name: PIXUS ip4100 manufactured by Canon Inc.), inkjet recording was performed on four types of plain paper shown in Table 3. During ink jet recording, a check pattern (a pattern in which 100% density and 0% 1.5 mm squares were alternately combined) was created to obtain a yellow / white printed matter with high contrast. The white portion is a plain paper background portion that is not colored with ink.
In addition, an image pattern was created so that gradations with several levels of reflection density were obtained, and a printed matter with a gradation of yellow color gradation was obtained.
When performing a visual judgment in the water resistance test, a check pattern print was used.
The dye residual ratio measurement in the water resistance test was performed using a gradation printed matter, and the reflection density was measured for a portion where the reflection density D value of the printed matter before the test was closest to 1. The reflection density was measured using a color measurement system (trade name: SpectroEye, manufactured by GretagMacbeth).
Various test methods for recorded images and evaluation methods for test results are described below.

Table 3
Plain paper 1
Product name LBP PAPER LS-500 manufactured by Canon Inc.
Plain paper 2
Product name Multipurpose Paper made by Hewlett Packard
Plain paper 3
Product name All-in-One Printing Paper made by Hewlett Packard
Plain paper 4
Seiko Epson double-sided high-quality plain paper KA4250NPD

(C) Measurement of L *, a *, b *, and C * of the printed matter In the printed gradation printed matter, the brightness of the portion where the yellow reflection density Dy value is closest to 1.0 is measured using the above colorimetric system. L * value, a * value, b * value and saturation C * value were measured. The results for plain paper 1 are shown in Table 4, the results for plain paper 2 are shown in Table 5, the results for plain paper 3 are shown in Table 6, and the results for plain paper 4 are shown in Table 7, respectively.

Table 4
Plain paper 1
L * a * b * C * C * / L *
Example 7 82.7 9.2 78.5 79.1 0.96
Example 8 83.1 7.6 77.5 77.9 0.94
Example 9 82.0 7.7 79.9 80.3 0.98
Comparative Example 1 88.0-5.2 75.3 75.5 0.86

Table 5
Plain paper 2
L * a * b * C * C * / L *
Example 7 84.2 11.0 77.0 77.8 0.92
Example 8 84.8 7.9 76.1 76.5 0.90
Example 9 83.6 10.8 76.2 78.2 0.94
Comparative Example 1 89.8-5.4 74.1 74.3 0.83

Table 6
Plain paper 3
L * a * b * C * C * / L *
Example 7 83.9 11.0 77.0 77.8 0.93
Example 8 84.9 8.1 78.3 78.7 0.93
Example 9 83.9 10.7 76.2 77.0 0.92
Comparative Example 1 89.3 -4.2 75.2 75.3 0.84

Table 7
Plain paper 4
L * a * b * C * C * / L *
Example 7 81.2 6.4 72.9 73.2 0.90
Example 8 82.3 2.9 68.4 68.4 0.83
Example 9 81.5 4.8 73.6 73.7 0.90
Comparative Example 1 86.0-6.6 66.6 66.9 0.78

(D) Water resistance test 1 (evaporation drying test)
One drop of ion-exchanged water was dropped on the check pattern printed matter that had been dried for 24 hours after printing, and then naturally dried. After drying, the degree of pattern bleeding was visually evaluated and evaluated in three stages according to the following criteria.
There is no bleeding at all (it cannot be determined where it was dripped).
There is almost no bleeding (the place where it was dripped can be identified) .... △
Obviously blurred ...
The results are shown in Table 8.

(E) Water resistance test 2 (immersion test)
A check pattern printed matter dried for 24 hours after printing was immersed in ion-exchanged water for 1 hour. After drying, the degree of color fading of the colored part of the pattern and the degree of coloring of the white part were visually evaluated and evaluated in three stages according to the following criteria.
There is no fading or coloring at all ...
Some color fading and coloring can be seen ...
Clearly discoloration and coloring can be seen ...
The results are shown in Table 9.

(F) Water resistance test 3
The gradation printed matter dried for 24 hours after printing was immersed in ion-exchanged water for 1 hour. After drying, the reflection density was measured using the color measurement system. After the measurement, the dye residual ratio was calculated by (reflected density after test / reflected density before test) × 100 (%), and evaluated in three stages according to the following criteria.
Dye remaining rate is 90% or more ...
Dye remaining rate is 80% or more and less than 90%.
Dye residual ratio is 50% or more and less than 80%.
Dye remaining rate is less than 50% ...
The results are shown in Table 10.

Table 8 Results of water resistance test 1

(Plain 1) (Plain 2) (Plain 3) (Plain 4)
Example 7 △ ○ ○ ○
Example 8 ○ ○ ○ ○
Example 9 × ○ ○ ○
Comparative Example 1 × ○ ○ ○

Table 9 Results of water resistance test 2

(Plain 1) (Plain 2) (Plain 3) (Plain 4)
Example 7 ○ ○ ○ ○
Example 8 ○ ○ ○ ○
Example 9 ○ △ △ △
Comparative Example 1 × △ △ ×

Table 10 Results of water resistance test 3

(Plain 1) (Plain 2) (Plain 3) (Plain 4)
Example 7 ◎ ◎ ◎ ◎
Example 8 ◎ ◎ ◎ ◎
Example 9 ◎ ◎ ◎ △
Comparative Example 1 △ ○ ◎ △

  As is clear from the results in Tables 4 to 7, the inks of Examples 7 to 9 have a saturation C * value superior to that of Comparative Example 1 in any of plain papers 1 to 4, and the saturation C * is a lightness L *. As for the value C * / L * divided by 1, each example is 0.83 to 0.98, and Comparative Example 1 is 0.78 to 0.86, whereas when compared with the same plain paper The minimum value is 5 points for plain paper 4 and the maximum value is 12 points for plain papers 1 and 4, and it can be seen that it has a yellow hue with high saturation.

  In addition, from the evaluation results of the water resistance test 1 in Table 8, it can be seen that there is a difference in plain paper 1 and that Examples 7 and 8 have high water resistance. In this test, Example 9 and Comparative Example 1 were approximately the same level of water resistance.

  From the evaluation results of the water resistance test 2 in Table 9, the inks of Example 7 and Example 8 showed very good water resistance in any of plain papers 1-4. In addition, when plain paper 1 and plain paper 4 were used in this test, the ink of Example 9 was found to have water resistance that was clearly superior to that of Comparative Example 1.

  From the evaluation results of the water resistance test 3 in Table 10, the water resistance of each example was superior to that of Comparative Example 1 for plain paper 1 and plain paper 2, and the same level of water resistance was exhibited for plain paper 3. For plain paper 4, Examples 7 and 8 showed water resistance that was clearly superior to that of Comparative Example 1, and Example 9 was as water resistant as Comparative Example 1.

  From the above results, the water-soluble azo compound of the present invention is suitable for preparing an ink composition for ink jet recording, and has various fastness properties, in particular, water resistance in various types of plain paper as compared with conventional dyes. Excellent in water solubility, high water solubility, good chroma and clear hue. From these characteristics, it is clear that the azo compound of the present invention is a very useful compound as various recording ink dyes, particularly yellow dyes for inkjet inks.

Claims (12)

Water-soluble azo compound represented by the following formula (1) or a salt thereof

(In the formula (1), R represents an alkyl group having 1 to 4 carbon atoms,
n is an integer of 1 or 2,
x is an integer from 2 to 4,
The group A represents a divalent linking group represented by any one of the following formulas (2) to (4). )

(In formula (2), y represents an integer of 2 to 6.)

(In formula (4), w represents an integer of 1 to 4). The water-soluble azo compound or a salt thereof according to claim 1, wherein R in the formula (1) is a methyl group, n is 1, and x is 3. The water-soluble azo compound or a salt thereof according to claim 1, which is represented by the following formula (5).

An ink composition comprising the water-soluble azo compound according to any one of claims 1 to 3 or a salt thereof as a coloring matter. The ink composition according to claim 4, further comprising a water-soluble organic solvent. The ink composition according to claim 4 or 5, which is for ink jet recording. In an ink jet recording method for recording on a recording material by ejecting ink droplets according to a recording signal, the ink composition according to any one of claims 4 to 6 is used as an ink. Method. The ink jet recording method according to claim 7, wherein the recording material is an information transmission sheet. 9. The ink jet recording method according to claim 8, wherein the information transmission sheet is a sheet having an ink receiving layer containing plain paper or a porous white inorganic substance. A colored body colored with the water-soluble azo compound according to any one of claims 1 to 3 or the ink composition according to any one of claims 4 to 6. The colored body according to claim 10, wherein coloring is performed by an ink jet printer. An ink jet printer loaded with a container containing the ink composition according to any one of claims 4 to 6.